Following a temporal bone fracture, a patient develops an epidural haematoma with the classical 'lucid interval'. The middle meningeal artery runs in a groove on the temporal bone. At which point is it most vulnerable to rupture?
- A Pterion — where the frontal, parietal, temporal, and sphenoid bones meet (thinnest part of skull) ✓
- B Vertex of the skull
- C Posterior cranial fossa floor
- D Anterior cranial fossa, near the cribriform plate
Correct answer: A. Pterion — where the frontal, parietal, temporal, and sphenoid bones meet (thinnest part of skull)
Explanation
The pterion is the H-shaped suture formed by the articulation of the frontal, parietal, temporal, and greater wing of sphenoid bones on the lateral surface of the skull. It is the thinnest part of the skull (2-3 mm) and overlies the anterior branch of the middle meningeal artery. A blow to the temporoparietal region (squash ball, cricket ball) fractures the pterion and tears the middle meningeal artery, causing an epidural (extradural) haematoma. The lens-shaped (biconvex/lenticular) hyperdense hematoma on CT is characteristic.
Reference: BD Chaurasia's Human Anatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.